Добірка наукової літератури з теми "Li metal free full cell"

Anode-free Li metal batteries are considered the ultimate configuration for next-generation high energy-density Li-based batteries due to the elimination of excess Li metal. However, the limited Li source aggravates issues such as dendrite growth and “dead” Li formation. Any Li loss caused by the SEI formation and dead Li has a great influence on the performance of the full cell. Here, we introduce LiI with shuttle effect to suppress the Li dendrites and reactivate the dead Li in the anode-free LiFePO4 (LFP) ∣Cu full cells. During cycling, the iodine transforms between I− and I3 −, and a chemical reactions occur spontaneously between I3 − and Li dendrites or dead Li. The generated Li+ in the electrolyte remains active in the following cycling. The anode-free LFP∣Cu cells deliver an initial discharge capacity of 139 mAh g−1 and maintain capacities of 100 mAh g−1 with a capacity retention of 72% after 100 cycles. Both the anode-free LFP∣Cu coin cells and pouch cells with LiI additive show much-improved performances. This work provides a new strategy for high-performance anode-free Li metal batteries.

Using the ideal Lithium metal (Li) as an anode material for Lithium metal batteries (LMBs) displays considerable potential in enlightening energy density and power density than conventional lithium-ion batteries (LIBs). Nevertheless, the low Coulombic efficiency, significant volume changes during operation, which reduces electrode mechanical stability, and Lithium (Li) dendrites formed and growth from nonuniform Li deposition during cell operation causes safety issues and limits potential uses of Li as an anode material for LMBs. Recently, anode free (Lithium free) lithium metal batteries (AFLMBs) protocol have got great attention due to their higher energy density, reduces cell weight, costs effectiveness, easy fabrication, and safety during the process of cell manufacture. Nevertheless, in AFLMBs, the uncontrolled plating of lithium on bare copper foil imposes a more severe lithium dendrite growth. Hence, planning proper design on an anode current collector which is appropriate for AFLMBs is essential. Herein, we handle the growth of lithium dendrite by guiding lithium metal deposition site to the backside of the gold-sputtered perforated polyimide film (PI@Au), which used as an anode current collector. Hence, metallic lithium (Li) starts to plate on the modified PI@Au surface, and sequentially, growth of Li takes place in the direction away from the separator face (ASF). This backside deposition and growth approach allow the battery to operate safely, even when lithium dendrite exists. . Surprisingly, the dendrite-free surface on the separator-facing side (SF) of PI@Au anode reveals significantly improved cycling stability. As a result PI@Au//Li cell (2 mAh/cm2 and 0.5 mA/cm2) offers stable cycling performance for 1400 h without significant voltage polarization. Conversely, Cu//Li cell cycling with results higher voltage hysteresis and face short-circuit below 600 h at same working conditions. Besides, PI@Au//LFP anode-free full cell configuration maintained 20 % capacity retention (CR) with average Coulombic efficiency of 98.7 % after 340 cycles (0.5 mA/cm2). On the contrary, the Cu//LFP full cell runs only for 165 cycles under the same value of CR. Guiding the plating of Li to the backside of perforated polyimide film insights into an innovative technique for developing ultra-safe AFLMBs and also proves the viability of the electrical insulator substrates as anode current collectors by improving their conductivity and lithiophilicity.

Copper oxide is coated in situ on a phase inversion-derived Cu scaffold for Li metal anodes, which exhibit a low nucleation overpotential, high coulombic efficiency and a long lifespan. The scaffold-Li//NCM full cell exhibits good cycling stability.

Current lithium-ion batteries (LIBs) are approaching their energy density limits and thus may not keep up with the ever-increasing demand for higher specific energy density in today’s energy storage and power applications. Anode-free lithium metal batteries (AFLMBs) utilize the full theoretical capacity of Li metal anode (3860 mAh g-1, ten times higher than lithiated graphite) and offer lower cost and better safety than cells with Li excess. However, due to the low efficiency of Li deposition and stripping, AFLMBs suffer from rapid capacity loss. In this presentation, we will discuss a unique coin cell configuration design with high compression for AFLMBs. The high pressure leads to more stable cycling performance, providing a more accurate assessment of AFLMBs.1 A carbonate-glyme hybrid electrolyte for AFLMB is demonstrated with a capacity retention of 73% for 50 cycles. The hybrid electrolyte possesses a unique solvation structure, where diglyme solvates both Li-ions and film-forming additive, while carbonates dilute the mixture, enabling facile ion migrations.2 C. Zhou, A. J. Samson, M. A. Garakani, and V. Thangadurai, J. Electrochem. Soc., 168, 060532 (2021). C. Zhou et al., Energy Storage Mater., 42, 295–306 (2021) https://doi.org/10.1016/j.ensm.2021.07.043.

The anode-free lithium metal battery (AFLMB) is attractive for its ultimate high energy density. However, the poor cycling lifespan caused by the unstable anode interphase and the continuous Li consumption severely limits its practical application. Here, facile one-step heat treatment of the Cu foil current collectors before the cell assembly is proposed to improve the anode interphase during the cycling. After heat treatment of the Cu foil, homogeneous Li deposition is achieved during cycling because of the smoother surface morphology and enhanced lithiophilicity of the heat-treated Cu foil. In addition, Li2O-riched SEI is obtained after the Li deposition due to the generated Cu2O on the heat-treated Cu foil. The stable anode SEI can be successfully established and the Li consumption can be slowed down. Therefore, the cycling stability of the heat-treated Cu foil electrode is greatly improved in the Li|Cu half-cell and the symmetric cell. Moreover, the corresponding LFP|Cu anode-free full cell shows a much-improved capacity retention of 62% after 100 cycles, compared to that of 43% in the cell with the commercial Cu foil. This kind of facile but effective modification of current collectors can be directly applied in the anode-free batteries, which are assembled without Li pre-deposition on the anode.

The employment of lithium (Li) metal is crucial to sustainable Li metal batteries (LMBs) with realistically high energy density. The management and usage of Li in reality, however, remain high challenge due to the desirable of obtaining an undamaged Li structure arising from the indispensable in extenuating strongly environmental dependence of Li during stored procedure and minimizing the Li depletion and pulverization on long-term cycles. Herein, we impair the molecular hydrogen bonding cooperation between lithium and water molecules on the surface of Li to demonstrate an achievement of environmental independent and durable Li via integrating a reinforced molecular hydrophobic interface on the surface of Li. As a result, the molecular hydrophobic interface modified Li metal can exhibit dendrite-free Li deposition and achieve stable operation for 200 cycles in Li-S full cell at a current of 1 C.

An Li metal anode has been proposed as a promising candidate for high energy density electrode material. However, the direct use of Li metal can lead to uncontrollable dendrite growth and massive volume expansion, which generates severe safety hazards and hinders practical application. Herein, we developed a novel Li anode by thermal infusion into three-dimensional (3D) carbon cloth (CC) modified with lithiophilic CuO nanorod arrays (denoted as Li@CuO−CC). The 3D CC offers sufficient space for Li storage and adequate electrolyte/electrode contact for fast charge transfer. The uniformly distributed CuO nanorod arrays can improve the lithiophilicity of CC and redistribute the Li-ion flux on the substrate, leading to uniform Li stripping/plating behavior. As a result, the Li@CuO−CC electrode exhibits a dendrite-free feature and superior cycling performance over 1000 h with low overpotential (12 mV) at a current density of 1 mA cm−2 in the symmetrical cell without significant fluctuations. When coupled with an LiFePO4 cathode, the full cell displays high specific capacity (133.8 mAh g−1 at 1 C), outstanding rate performance, and cycle stability (78.7% capacity retention after 600 cycles at 1 C). This work opens a new approach for the development of construction of an advanced anode for Li metal batteries.

Discovering new chemistry and materials to enable rechargeable batteries with higher capacity and energy density is of paramount importance. While Li metal is the ultimate choice of a battery anode, its low efficiency is still yet to be overcome. Many strategies have been developed to improve the reversibility and cycle life of Li metal electrodes. However, almost all of the results are limited to shallow cycling conditions (e.g., 1 mAh cm−2) and thus inefficient utilization (<1%). Here we achieve Li metal electrodes that can be deeply cycled at high capacities of 10 and 20 mAh cm−2 with average Coulombic efficiency >98% in a commercial LiPF6/carbonate electrolyte. The high performance is enabled by slow release of LiNO3 into the electrolyte and its subsequent decomposition to form a Li3N and lithium oxynitrides (LiNxOy)-containing protective layer which renders reversible, dendrite-free, and highly dense Li metal deposition. Using the developed Li metal electrodes, we construct a Li-MoS3 full cell with the anode and cathode materials in a close-to-stoichiometric amount ratio. In terms of both capacity and energy, normalized to either the electrode area or the total mass of the electrode materials, our cell significantly outperforms other laboratory-scale battery cells as well as the state-of-the-art Li ion batteries on the market.

Li metal-based all-solid-state batteries (ASSBs) can potentially combine the high energy of Li metal anodes and the safety of ASSBs. Among Li metal-based ASSBs, lithium-free or anodeless ASSBs are considered optimal battery configurations because of their higher energy density and economic advantages attributed to the absence of Li metal during the battery assembly process. Despite the extensive interest in Li-free ASSBs, they continue to suffer from low Coulombic efficiency and poor cycle performance. One reason for this inferior performance is the unstable interface between the current collector and solid electrolyte (SE), which can eventually lead to inhomogeneous Li deposition, dendritic Li growth, and internal short circuits. Various approaches including 3D porous anodes have been proposed to control the Li deposition behavior and improve the reversibility of anodeless ASSBs; however, there is no clarity on the mechanism and conditions for determining the Li deposition behavior in this emerging system. In this study, we systematically investigate the Li deposition behavior depending on the pore size of 3D anode and successfully demonstrate the strategy to obtain a highly reversible 3D porous anode for Li-free ASSBs. We found that more Li deposits could be accommodated within the pores of the anode with a smaller pore size using stacked Ni particles as the Li-hosting porous anode; this implies that the Li movement into the anode occurs via diffusional Coble creep. We proposed the modification of the Ni surface with carbon coating and Ag nanoparticle decoration (Ni_C_Ag particles) to further improve the Li storage capacity of the Ni-based 3D anode and, thereby, secure the interfacial contact between the 3D Ni anode and SE. The resulting Ni_C_Ag 3D anode successfully accommodated the entire Li deposit of 2 mAh cm−2 within the porous architecture without the separation of the anode/SE interface. We clarified the improved Li storage capacity of the Ni_C_Ag anode as follows. (1) C and especially Ag electrochemically react with Li ions above 0 V; thus, Li ions can be transported to 3D Ni_C_Ag porous anode before Li deposition at the SE/anode interface at < 0 V. Further, the high Li ion diffusion coefficient of lithiated carbon and Li-Ag alloy can further reduce Li ions within the pores of the 3D anode; therefore, Li deposition can occur within the porous 3D Ni anode. (2) Lithiophilic C and Ag facilitated the movement of Li via diffusional Coble creep. In particular, Ag with solid solubility in Li (Li(Ag)) can significantly enhance Li adatom mobility because of the identical structure of Li(Ag) with pure Li. (3) Li(Ag) is widely known to lower the energy barrier for Li nucleation. With the significantly reduced nucleation overpotential and interfacial resistance, the Ni_C_Ag anode showed high reversibility in Li deposition and stripping. The Ni_C_Ag anode could be cycled for more than 60 and 100 cycles with Li3PS4 and Li6PS5Cl0.5Br0.5 SE in half cells with a capacity limit of 2 mAh cm−2 and a current density of 0.5 mA cm− 2maintaining the CE of 97.9% and 96.9 %, respectively. Further, the synergistic effects of the stable anode/SE interface and reduced nucleation energy barrier enable stable NCM full-cell cycling at a room temperature of 30 °C. The NCM811 cathode/Ni_C_Ag anode full cell in the Li-free configuration showed an initial areal discharge capacity of 2 mAh cm−2, and it operated stably with a CE of 99.47% for 100 cycles. Figure 1

This dissertation comprehensively speaks about the state of research in Li/S electrochemical system. Li-ion batteries are all over in gadgets, laptops and almost in every portable consumer electronics. But, future energy storage demand for electrical mobility and smart grids asking for much higher energy density, sustainable and cheaper solutions. Lithium-sulfur (Li/S) technology is one of the promising solutions to such demands as it can offer five times high energy density than that of state of art Li-ion technology. Li/S system can be potentially regarded as a sustainable and cheaper technology owing to abundancy and benignity of sulfur. However, the insulating nature of sulfur and Li2S, free solubility of lithium polysulfide (LiPS) in the electrolyte, shuttling of LiPS across separator and use of metallic lithium as anode challenge the scientific community to offer some practical solutions for its commercialization . The effort can be done in various dimensions to realize stable and long-life Li/S batteries. Various startegies have been proposed to realize efficient and stable sulfur and silicon electrodes. In the end, a Li metal free Si/S full cell has been realized.

This paper highlights our progress in developing pristine single-walled carbon nanotubes (SWCNTs) into functional materials for lightweight, conductive cathodes in lithium air (Li-air) batteries. We outline a process to produce foams of single-walled carbon nanotubes using liquid processing routes that are free of additives or surfactants, using polar solvents and electrophoretic deposition. To accomplish this, SWCNTs are deposited onto sacrificial metal foam templates, and the metal foam is removed to yield a freestanding, all-SWCNT foam material. We couple this material into a cathode for a Li-air battery and demonstrate excellent performance that includes first discharge capacity over 8200 mAh/g, and specific energy density of ∼ 21.2 kWh/kg (carbon) and ∼ 3.3 kWh/kg (full cell). We further compare this to the performance of foams prepared with SWCNTs that are dispersed with surfactant, and our results indicate that surfactant residues completely inhibit the nucleation of stable lithium peroxide materials — a result measured across multiple devices. Comparing to multi-walled carbon nanotubes produced using the same technique indicates a discharge capacity of only ∼ 1500 mAh/g, which is over 5X lower than SWCNTs in the same processing technique and material architecture. Overall, this work highlights SWCNT materials in the absence of impurities introduced during experimental processing as a lightweight and high performance electrode material for lithium-air batteries.

The objective of this paper is to experimentally investigate the machinability of nano-TiC reinforced Nickel based super alloy Inconel 718 fabricated by direct metal selective laser melting (SLM). Four 10×10×3 square test coupons were fabricated with different amount of nano-TiC: (1) pure Inconel 718, (2) Inconel 718+0.25% TiC, (3) Inconel 718 + 0.5% TiC, of 508 microns. The machinability of the four materials were examined in terms of cutting forces, tool wear and chip morphology. Three level of federates (1.0, 1.5 and 2.0 um/flute) and three level of spindle speeds (12,000, 15,000 and 18,000 rpm) were selected and a 32 full factorial experiment was performed on each test coupon. Full immersion slotting was selected with a fixed axial depth of cut at 20 microns. The SEM images of the tools reveal that the dominant wear mechanisms were abrasive wear at the tool tip and flank face. The adhesion and build up edge were also common. The wear rate increases with the addition of nano-TiC. The loss of the AlTiC coating will result in accelerated wear, which was observed for machining of nano-TiC reinforced Inconel 718, but not on pure Inconel 718. The edge chipping and abrasive wear at the tool tip reduced the effective cutting diameter, enlarged the edge radius, and caused the increase of the cutting force. For all the materials tested, the cutting chips had serrated edge on the free surface and much smoother surface on the other side, which suggests that a cyclic chip formation of alternating high shear strain followed by low shear strain. This is in agreement with the chip formation mechanism for the Inconel 718 fabricated with conventional method rather than DMLS. The serration is more severe with the and (4) Inconel 718 + 1% TiC. Tensile tests were performed on all four material and the material strength increases with the increase of the TiC content up to 0.5% then plateaued. The elongation drop significantly with the inclusion of TiC in Inconel substrate. Micro-endmilling experiments were conducted using AlTiN coated WC micro-mill with nominal diameter addition of nano-TiC. The cutting forces were collected with a Kistler 3-axial load cell 9017B. The cutting forces increases with the increase spindle speed (hence surface speed) within the range examined, but the effect of feedrate is not statistically significant. The cutting forces were much higher for TiC reinforced Inconel and the magnitude of the cutting forces increases with the increase of the weight percentage of TiC contents.

Abstract With the ever-increasing demand to reduce the product development cycle, Harley-Davidson Motor Company (HDMC) utilizes diverse CAE (Computer-Aided Engineering) tools to develop its motorcycles. These CAE tools assist resolving fluid, thermal and/or structural design refinements and challenges while minimizing the need to use physical models or prototypes, to achieve our goal of a complete virtual product development cycle and decreased time-to-market. The growing computational power and resource availability enables the option to simulate more complex physics with higher resolution and accuracy. The compatibility of the various CAE tools available provide options to choose the best tool based on the physics required and integrate with other applications. This paper demonstrates an automated integration of a compact and complex vehicle CFD (Computational Fluids Dynamics) – CHT (Computational Heat Transfer) analysis, which provides a predictive solution for flow-thermal state of the vehicle, exhaust system, rider ambient, and electronic component internals. The focus of this paper is the methodology that encompasses physics of these models, the associated meshes, and the automated integration of the two. The paper discusses the utilization of aforementioned software tools to support a highly advanced and complex vehicle CAE flow-thermal predictive solution. Furthermore, the paper talks about how to arrive at a robust and detailed prediction of thermal state of vehicle with its electronic component internals such as LED (light-emitting diode), PCB (printed circuit board), and IC (integrated circuit) semiconductors, all driven by a combined external and internal thermo-fluidic flow and electronic operation waste heat. The paper exhibits the versatility of a single CAE model which combines a full vehicle external aerodynamics CFD model and a stripped down CHT model consisting of powertrain, exhaust, cooling system, rider, and partial bodywork which are significant to meet the analysis objectives. The early intervention of these CAE techniques in the motorcycle development process accelerates the component design evaluation by eliminating/modifying initial designs based on the analyses results and assists in making educated and well-informed decisions. The visual representation of the analysis findings provides extremely valuable information which are sometimes not possible to obtain in a physical test environment and can save re-testing time and avoid delays as the test community strives to get data from those systems and components. Our integrated CFD-CHT analysis method is comprised of full vehicle external aerodynamics CFD module with the export of local air conjugate heat transfer coefficients and reference temperatures, following the import of solid surface boundary temperatures computed via the computational heat transfer (CHT) module, and the automated integration and boundary data exchange iterations between the two modules. CHT module computes solid surface temperature of all heat emitting, and / or absorbing, vehicle components such as exhaust / powertrain, starter motor, and all electronic heat producing components, as well as manikin riders and vehicle components that may be impacted by heat emitting components. All three modes of heat transfer, including vehicle ambient radiation boundary conditions, are being considered in the model. Internal details of electronic components including, and not limited to, MOSFET (metal-oxide semiconductor field-effect transistor) semiconductors, LEDs, Thermal Interface Material (TIM), heat sink, etc., are included in the CHT module. The automated integration of CFD-CHT modules results in a converged full vehicle thermo-fluidic state of the vehicle in a steady-state or pseudo-transient duty. Similar approach is undertaken for EVs (electric vehicles) with details to the electronic PCB, and its components, and the battery pack Li-Ion cell internal levels.